<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>CSS行高</title>
  <style>
    .cc1 {
      font-size:12px;
    }
    .cc2 {
      font-size:18px;
    }
    .cc3 {
      font-size:24px;
    }
  </style>
</head>
<body>
  <div style="border:solid 1px red;">
    <span style="background:blue;color:#fff;font-size:20px;line-height:60px;">
        居中xfg&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;
    </span>
  </div>
  <div class="c1">
    <span class="cc1">第一段</span>
    <span class="cc2">第二段</span>
    <span class="cc3">第三段</span>
  </div>
  <div style="background:red">
    <span>文字</span>
    <img src="test.png"/>
  </div>
</body>
</html>
